The present invention relates to web material incorporating a tackifier and to pads formed from such material. The invention also relates to a dispenser for pads formed from web material which incorporates a tackifier.
So-called tack cloths, or tack rags, for use in removing dust or similar foreign matter from surfaces are already known and are widely used, both in industry and in the domestic situation. Among the largest users of tack cloths are vehicle manufacturers, and also vehicle repairers such as bodyshops, who apply paints and lacquers to large areas of vehicle surfaces. To enable a flawless finish to be achieved when painting/repainting a vehicle surface, it is essential that the surface should be maintained free of foreign particles and, even when painting/repainting operations are carried out in closed areas provided with air conditioning and filter systems, tack cloths are still employed to ensure that every foreign particle is removed.
Generally, tack cloths comprise some form of textile material which has an open structure and is treated with a tackifier to give it a sticky or tacky character. When such a cloth is rubbed over a surface, foreign matter (such as dust) which is present on the surface will adhere to the cloth and be removed. Various forms of tack cloth are described in, for example U.S. Pat. Nos. 2,633,958, 2,955,962, 3,016,555, 3,028,618, 3,208,093, 3,307,214, 3,658,578, 5,198,292 and 5,198,293 and Canadian Patent Specification No. 1,305,839. Examples of commercially available tack cloths or tack rags include xe2x80x9cEvercoat Professional Tack Clothxe2x80x9d, commercially available from Fibre Glass Evercoat Co., Inc., of Cincinnati, Ohio, U.S.A.; xe2x80x9cCrystal Tack Clothxe2x80x9d, commercially available from Bond Chemical Products Company of Chicago, Ill., U.S.A.; xe2x80x9cLint Free Tack Clothxe2x80x9d, commercially available from Datco International, of Hazel Park, Mich., U.S.A. A tack cloth comprising a pad of a non-woven web material impregnated with a tackifier has also been available, under the trade designation xe2x80x9c0966 1xe2x80x9d from Minnesota Mining and Manufacturing Company of St. Paul, Minn., U.S.A.
The present invention is directed to the provision of web material incorporating a tackifier, suitable for use particularly as pads to enable dust and similar foreign matter to be removed effectively from surfaces. The present invention is also concerned with providing a dispenser for such pads.
The present invention provides a web material comprising a non-woven cross-laid web which is needle-tacked and chemically- and/or thermally-bonded, and at least one major surface of which is impregnated with a tackifier.
The non-woven web may comprise synthetic fibres, for example nylon, polyester, polypropylene, or mixtures thereof
The tackifier may comprise a pressure-sensitive adhesive, for example an acrylic pressure-sensitive adhesive. The non-woven web may be impregnated throughout with the tackifier. The non-woven web may also comprise a binder resin, for example an ethylene vinylacetate copolymer.
The present invention also provides a tack pad comprising a pad of web material as defined above. The pad may further comprise a liner material located on, and releasably adhering to, one surface of the pad, the liner material having a low adhesion coating on the side remote from the pad. The liner material may, for example be a paper material having a polyethylene coating on the side remote from the non-woven web.
The present invention further provides a method of making a web material comprising the steps of forming a non-woven, cross-laid web which includes thermo-bonding fibres, needle-tacking the web, impregnating at least one surface of the web with a tackifier, and applying heat to thermally-bond the web and cure the tackifier. Advantageously, the steps of thermally bonding the web and curing the tackifier are carried out simultaneously. Preferably, the tackifier is applied to the web as an aqueous dispersion.
The method may further include the steps of impregnating the web with a binder resin and applying heat to cure the binder resin. Preferably, the binder resin is applied to the web as an aqueous dispersion.
Advantageously, the binder resin is applied to the web simultaneously with the tackifier and is cured simultaneously with the tackifier.
The thermobonding fibres used in a method in accordance with the invention may be multi-component fibres and may comprise polyamide, polyethylene, polyester, polypropylene, or mixtures thereof.
The step of impregnating at least one surface of the web with a tackifier may comprise applying to the web, as an aqueous dispersion, a mixture of an acrylic pressure-sensitive adhesive and an ethylene vinylacetate copolymer. The mixture may also comprise a surfactant and a catalyst.
The present invention further provides a dispenser for pads of material, the dispenser being shaped to contain a stack of the pads in position over an outlet opening in the bottom of the dispenser, and to permit access to one edge of the bottom pad of the stack whereby the bottom pad can be pulled downwardly away from the stack through the outlet opening.
The dispenser may have a loading opening through which a stack of pads can be placed in the dispenser. The loading opening may be in the front of the dispenser and in communication with the outlet opening, thereby providing the said access to one edge of the bottom pad of a stack in the dispenser. The dispenser may include a cover for the loading opening, the cover being movable between an open and a closed position. The dispenser may include stop portions which project into the loading opening to prevent a stack in the dispenser moving out of the dispenser through the loading opening.